Electrically heated floor cover



INVENTOR ATTORNEY v Stanleyllfionbtere.

S. M. PONTIERE ELECTRICALLY'HEATED FLOOR COVER Flled May 10, 1951 Nov. 25, 1952 Patented Nov. 25, 1952 UNITED STATES PATENT OFFICE Claims.

My invention relates generally to electrical heating units and particularly to flexible portable auxiliary electric heaters.

There are many uses for the flexible portable heaters of my present invention. However, a particularly practical and economical use is for heating cottages with unheated or underheated rooms, poorly insulated floors and the like.

H'eretofore, heat panels, radiant type floor heaters and similar installations require a considerable amount of equipment and expensive installation problems. Accordingly, an object of my invention is to provide a novel electrically heated portable floor covering, such as a rug, a foot pad or the like, whereby all but very minor and inexpensive installation problem are eliminated.

Another object is to provide a yieldably resilient floor covering which may be used as a decorative rug with or without the use of the electrical heating means comprising a part thereof.

Still another object is to provide a laminated structure including a heater element confining pad cross channeled to effectively distribute the heat from the heater elements throughout the pad, to thereby develop a maximum heated area for heat radiation therefrom.

A further object is to provide in combination with the heated rug, pad or the like, a remote thermostatic control responsive to room temperatures.

Still a further object is to arrange and connect the heater elements in groups operable in series progressively and additively to thereby utilize one, two or all of the heater elements together.

Yet another object is to provide a novel retaining means for the individual cables of the heating elements.

With these and other objects in view which will become apparent as my invention is fully understood, the same reside in the novelty of construction, combination and arrangement of elements hereinafter described in detail and distinctly claimed in the appended claims.

The description should be read in conjunction with the accompanying drawings of one embodiment of my invention in which like characters of reference designate like or similar elements throughout the several views.

Figure 1 is a general perspective view of the parts of the invention having one end separated to clearly illustrate the structural features thereof.

Figure 2 is a fragmentary cross section view taken through the heater coil retainer pad along the line 3-3 of Figure 1.

Figure 3 is a top plan View of one arrangement of the groups of heater coils in the retainer pad and one arrangement of electrical switch control therefor.

Referring in detail to the drawings and first with particular reference to Figure 1, there is shown a two-ply structure comprising an upper surface, such as a sheet or rug l0 and an undersurface, such as a novel cable retaining pad l2. The sheet or rug surface may be of the approved wool or commercial standard rug faces with wear resistant qualities. Each surface of the rug could also be of plastic, rubber, hemp or cocoa, cotton or fabric and provided in colors suitable for decorating schemes. Commercial rugs could also be attached over the electric cable retaining pad l2, which could be sold independently of the rugs as a separate article of manufacture. The rugs may be secured to the pad [2 in any suitable manner or simply laid on the pad I2.

The novel cable retaining pad 12 is an important feature of my invention. This pad may be constructed of any suitable material such as hair felt, rubber, asbestos fabric, plastic, etc. Formed in the surface of the cable or heating coil retaining pad I2 are dovetail grooves l3, that is, grooves formed with a relatively larger interior area and a restricted small opening at the upper surface of the pad, see Figure 3. The restricted opening of each groove is defined by the peripheral edges 14 and I5 of the converging side walls of the groove. Thus with this formation the heat cable may be snapped by the edges into the enlarged part of the groove. Coil retaining grooves formed in this fashion are inherent retainers and grasp and secure the cable or coil 16 without additional labor or materials. Also unused grooves, which may be interconnected, as hereinafter explained, serve as pockets to retain the warm air and aid in distributing the heat available over the entire surface of the unit. These grooves are shown in a crisscross pattern to receive and retain the cable [6 of the respective heating elements A, B and C in coiled groups, but they may if desired be arranged and proportioned with respect to the shape of the room or floor plan to provide better heating results. For example, in Figure 2 the groups are shown in plan connected to a three-way switch [7. The several coiled groups are connected through the three-way switch l1, so as to be energized progressively and additively to energize one, two or all groups together. The opposite or underside of the cable or coil retaining pad 12 is preferably provided with a skid resistant backing l8 to prevent slipping or skidding on the floor.

The several grooves I3 may be interconnected by substantially horizontal air conduits l8 and the top surface of laminations l9 between the grooves formed with vertical air conduits 20 connecting with the horizontal conduits. This arrangement of air conduits will provide for maximum uniform heat distribution.

The heater element retaining pad I2 also provides a yieldably resilient base under foot and prevents marring and undue wear on the floor surface by the heating elements.

The particular cable used may be any known commercial heating cable of approximately /8" in diameter and available in several standard lengths. Such cable, for example, is made for use on 110 volts and 220 volts or in special cases 220 volts to 240 volts. It is so designed that the maximum temperature on the cable insulation when exposed to the ambient atmosphere at 50 degrees F. is approximately 112 degrees F. The insulation on such cable is extremely slow a eing and is heat resistant, has low water absorption and is of high dielectric strength.

Also any known -commercially approved thermostatic remote control and overload protective device such as 2! may be used having sufficient capacity for use with the length and type of cable selected. Specific load requirement calculations based on a figure of 2 watts per cubic foot for a room less than 2,000 cu. ft. are as follows;

A 1500 cu. ft. room would be approximately 12 feet wide by 8 feet high by 15 feet long and would require a 1,000 foot, 3,000 watt unit for use with 220 or 440 volts. Obviously this particular installation could not be considered readily portable due to its size and the necessary voltage. However, it is possible to make a portable rug or mat to fit the above room which would be entirely adequate. Two standard units of heating cable available for use on 110 volt to 120 volt house current are 60 foot, 250 watt type and 500 foot, 1500 watt type. The 60 foot length would be readily adaptable to a standard size rug or pad 30 inches by 60 inches and the larger size would be readily adaptable to a standard size rug or pad 9 feet by 12 feet.

Thus I have provided a novel heating unit requiring negligible space, of light weight and economical in operation, which is particularly valuable for use as a temperature responsive space heater for rooms of summer cottages and other unheated or underheated structures. Also, the unit is portable, need not be a permanent installation and eliminates radiators, steam or water lines, air ducts in the walls and other complicated and bulky structures necessary in heating systems.

While the foregoing specification describes and the drawings illustrate the specific details of only one embodiment of my invention, it is to be understood that the same is not limited by these details and is therefore susceptible to changes and modifications Within the scope of the appended claims without a departure from the spirit of my invention.

What is claimed is: v

1. A laminated structure for use as an electric space heater including a base portion formed with a plurality of grooves in the top surface thereof and a non-slip bottom surface, electric heater elements in the said grooves, conduits interconnecting said grooves, said heater elements being connected to a source of electric power through a switch, a thermostat responsive to space temperatures in the switch circuit, and an upper sheet with a top wear surface superimposed upon said base portion over the grooved side thereof, said base portion being of yieldably resilient material, to thereby resiliently yield under loads impressed upon the said wear surface of said upper sheet.

2. A laminated structure for use as an electric space heater including a base portion formed with a plurality of grooves in the top surface thereof and a non-slip bottom surface, electric heater elements in the said grooves, said heater elements being connected to a source of electric power through a switch, a thermostat responsive to space temperatures in the switch circuit, and an upper sheet with a top wear surface superimposed upon said base portion over the grooved side thereof, said base portion being of yieldably resilient material, to thereby resiliently yield under loads impressed upon the said wear surface of said upper sheet, and said grooves being of dovetailed configuration to provide airspaces adjacent the said electric cables of said heater elements retained within the said grooves below the top surface of said base portion.

3. An electric heater for rooms comprising a non-slip bottom surface and an electric heating element retaining top surface, electrically connected groups of heating elements in said top surface, said top surface being formed with crisscrossed dovetailed grooves for forming air spaces around the said heating elements confined therein; said airspaces being connected by conduits from each adjacent groove, control means for progressively and additively connecting each electrically connected group of heating elements to a source of electric power according to the demand for heat, and a rug mounted over the said heating element retaining top surface.

4. An electric heater for rooms comprising a non-slip bottom surface and an electric heating element retaining top surface, electrically connected groups of heating elements in said top surface, said top surface being formed with crisscrossed dovetailed grooves for confining said heating elements, and control means for progressively and additively connecting each electrically connected group of heating elements to a source of electric power according to the demand for heat, said dovetailed grooves being interconnected by ubstantially horizontal air conduits formed in the body of said top surface.

5. An electric heater for rooms comprising a non-slip bottom surface and an electric heating element retaining top surface, electrically connected groups of heating elements in said top surface, said top surface being formed with crisscrossed dovetailed grooves for confining said heating elements, and control means for progressively and additively connecting each electrically connected group of heating elements to a source of electric power according to the demand for heat, said dovetailed grooves being interconnected by substantially horizontal air conduits formed in the body of said top surface, and air conduits leading from said horizontal air conduits opening at the said heating element retaining top surface be tween the said dovetailed grooves.

STANLEY M. PONTILRE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 416,360 Dewey Dec. 3, 1889 1,320,585 Stewart Nov. 4, 1919 1,581,429 Donle Apr. 20, 1926 1,703,640 Schmidt-Predari Feb. 26, 1927 2,022,518 Payne Nov. 26, 1935 2,466,085 Dowrelio Apr. 5, 1949 2,575,987 York et al. Nov. 20, 1951 

